Internal combustion engines rely on cyclically collecting and igniting a combination of air and fuel in one or more combustion chambers. A given ignition drives a moving component disposed in a combustion chamber (e.g., a piston), ultimately generating a rotational force (e.g., via a crankshaft). The rotational force may be applied to rotate a wheel (e.g., via a transmission communicatively engaged to the crankshaft), thereby causing an associated vehicle to move.
When not actively generating a rotational force, the configuration of such an internal combustion engine may impede an existing movement of the vehicle. For example, a user may regulate an output force of an internal combustion engine by modulating an air intake throttle, for example via a pedal. When the user closes the throttle, little or no air travels into the internal combustion engine. At the same time, when pistons disposed in the internal combustion engine are drivingly engaged to one or more wheels (e.g., via a crankshaft engaged to a transmission, which in turn is engaged to one or more wheels), the wheels continue to drive the movement of the pistons within each respective combustion chamber as long as the vehicle is in motion. As such, the wheels drive a continued movement of the associated crankshaft and pistons disposed in the internal combustion engine, which effectively resists the continued movement of the vehicle. Further, while the throttle is closed or almost closed, the pistons push and pull against a static or almost static volume of air within each combustion chamber, further impeding the movement of the vehicle.